Data messaging in a communications network using a feature request

ABSTRACT

A messaging unit equipped with a cellular transceiver is attached to a truck trailer or a monitoring station located within a communications network. The messaging unit generates a data message in response to the occurrence of a reporting event. Upon generation of a data message, the messaging unit transmits the data message over the network via voice or data channels. Data messages may be sent over a data channel of the network using a feature request.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No.08/700,317, entitled “Data Messaging in Communications Network,” filedAug. 5, 1996 now U.S. Pat. No. 5,826,195 by William C. Kennedy, III andKenneth R. Westerlage, which is a continuation-in-part of U.S. patentapplication Ser. No. 08/465,525, entitled “Data Messaging in a CellularCommunications Network,” filed Jun. 5, 1995 by William C. Kennedy IIIand Kenneth R. Westerlage, now U.S. Pat. No. 5,544,225, issued Aug. 6,1996, which is a continuation application of U.S. patent applicationSer. No. 08/175,256, entitled “Data Messaging in a CommunicationsNetwork,” filed on Dec. 28, 1993 by William C. Kennedy III and KennethR. Westerlage, now U.S. Pat. No. 5,539,810, issued Jul. 23, 1996, whichis a continuation-in-part application of U.S. patent application Ser.No. 08/095,166, entitled “Method and Apparatus for a Nation-WideCellular Telephone Network,” filed on Jul. 20, 1993 by William C.Kennedy III and Kenneth R. Westerlage, now abandoned, which is acontinuation-in-part application of U.S. patent application Ser. No.07/826,521, entitled “Phantom Mobile Identification Number Method andApparatus,” filed on Jan. 27, 1992 by William C. Kennedy III and RobertJ. Charles, now abandoned.

TECHNICAL FIELD OF THE INVENTION

This invention relates generally to the field of telecommunications, andmore particularly to data messaging in a communications network.

BACKGROUND OF THE INVENTION

The proliferation of sophisticated communications systems has resultedin developments in data messaging. Data messaging collectively refers tothe transfer of information over voice or data channels of acommunications network. One application of data messaging is themonitoring of a group of items by causing the items to send datamessages to a remote location in response to a recognized reportingevents. A network of cellular telephone systems is a suitable conduitfor such data messaging, but the cost of using traditional cellularcommunication is prohibitive, both in terms of chargeable air time androamer fees.

Another problem with using traditional cellular networks for datamessaging is that the fragmentation of cellular service providersresults in disintegrated monitoring and control of cellular air traffic,which often contributes to fraudulent use of the cellular telephonenetwork. Increasing incidents of roamer fraud adds significantly to thecost of cellular air time, especially for nation-wide users of thecellular telephone network. To combat these problems, cellular serviceproviders are implementing authorization and verification procedures forvalidating roaming customers.

SUMMARY OF THE INVENTION

In accordance with the teachings of the invention, a method andapparatus for data messaging in a communications network substantiallyeliminate or reduce disadvantages and problems associated with prior artdata messaging systems.

In accordance with one aspect of the invention, a system forcommunicating information about an item using a cellular telephonenetwork includes a messaging unit coupled to the item. The messagingunit communicates, using the cellular telephone network, a featurerequest having data digits that represent information about the item. Aremote site coupled to the cellular telephone network receives thefeature request communicated by the messaging unit to obtain theinformation about the item.

An important advantage of the invention is that messaging units can senddata messages using the cellular telephone network by communicating afeature request having information on the monitored item. By using afeature request, the messaging unit can send information over existingcellular telecommunications equipment at a reduced cost and complexity.In a particular embodiment, the feature request communicated by themessaging unit includes a feature request code and data digits thatrepresent information on the monitored item.

In a particular embodiment, a messaging unit may be attached to orassociated with an item to be monitored. For example, a truck trailermonitoring system may use a messaging unit to communicate information onthe current position and/or status of a fleet of truck trailers. Also, amonitoring station may use a messaging unit to communicate informationgenerated by a metering device, such as a gas meter, electrical meter,other utility meter, or vending machine. In the latter example, thepresent invention allows flexible deployment of fixed monitoringstations in areas of cellular coverage without additional wireline orwireless equipment.

Other technical advantages are apparent from the attached description,figures, and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the invention and the advantagesthereof, reference is now made to the following description taken inconjunction with the accompanying drawings, wherein:

FIG. 1 is a,block diagram of a communications network for communicatinga variety of data messages in accordance with the teachings of theinvention;

FIG. 2 is a block diagram of a messaging unit operating within thecommunications network for sending and receiving a variety of datamessages in accordance with the teachings of the invention;

FIG. 3 is a flow diagram for sending a data message over a voice channelof the communications network using a modem handshake protocol inaccordance with the teachings of the invention;

FIG. 4 is a flow diagram for sending a data message over a data channelof the communications network in accordance with the teachings of theinvention;

FIG. 5 illustrates a block diagram of a nation-wide cellular systemconstructed according to the teachings of the present invention;

FIG. 6 illustrates another embodiment of a nation-wide cellular systemconstructed according to the teachings of the present invention;

FIG. 7 illustrates a communication unit constructed according to theteachings of the present invention;

FIG. 8 illustrates a telecommunications platform constructed accordingto the teachings of the present invention;

FIG. 9 is a flow diagram for transmission and reception of a presentmessage according to the teachings of the present invention;

FIG. 10 is a flow diagram of a call to a communication unit according tothe teachings of the present invention;

FIG. 11 is a flow diagram of a call from a communication unit accordingto the teachings of the present invention; and

FIG. 12 is a block diagram of a central host constructed according tothe teachings of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a block diagram of a communications network 10. Located withincellular system 14 of network 10 is a truck trailer 12 carried by a cab,barge, train, or other suitable transportation system. Also shown inFIG. 1 are monitoring stations 13 that are associated with a meteringdevice, such as a gas meter, electric meter, other utility meter,vending machine, or any other metering device that generates informationfor communication to a remote site. It should be understood that theinvention contemplates data messaging from any group of cargocontainers, vehicles, persons, metering devices, or other mobile orfixed items to be monitored.

Network 10 may be a cellular telephone network, but it may also beanother type of communications system, such as a specialized mobileradio (SMR) system, an enhanced specialized mobile radio (ESMR), apersonal communication services (PCS) system, or any other suitablecommunications system. Furthermore, network 10 may be comprised ofland-based transmission towers, space-based satellite transponders, or acombination of communications hardware in space or on land.Transmissions over network 10 may be analog, digital, or both withoutdeparting from the scope of the invention.

Truck trailer 12 and monitoring station 13 are equipped with a messagingunit 16, which contains a cellular transceiver for sending and receivingdata messages. The design of messaging unit 16 is discussed in detailwith reference to FIG. 2. Cellular system 14 includes a transmissiontower 18 and a mobile telecommunications switching office (MTSO) 20coupled to the transmission tower 18. It should be understood that eachcellular system 14 may comprise a plurality of transmission towers and aplurality of MTSOs.

MTSO 20 switches calls to and from the cellular system 14 and aland-based telecommunications system (not shown). MTSO 20 is alsocoupled to clearinghouse 22, which provides call information to MTSO 20through data link 23. For example, MTSO 20 can be configured to connectcalls only if clearinghouse 22 provides, for example, validationinformation indicating that the cellular phone involved has good creditor is authorized to make calls. Clearinghouse 22 may also maintain otherinformation, such as “roaming” phones' present locations and homesystems.

In existing cellular systems, companies such as GTE/TSI, EDS, and McCawprovide the clearinghouse function. This function may also be providedby MTSO 20 is or a home location register (HLR) associated with MTSO 20,clearinghouse 22, or other component in communications system 10, orprovided as a separate component in communications system 10. In oneembodiment, for example when communications system 10 supports aparticular cellular standard called IS41, the function of clearinghouse22 may be performed by MTSO 20. In this case, MTSOs 20 in communicationssystem 10 may communicate with each other for purposes of callprocessing without the need for the functionality provided byclearinghouse 22.

MTSO 20 is coupled to a telecommunications platform (“platform”) 24through a voice/data link 21. Clearinghouse 22 is also coupled toplatform 24 through data link 27 to provide platform 24 with informationgenerated by clearinghouse 22. In turn, platform 24 is coupled to host26 through voice/data link 29. Platform 24 may be coupled to any otherhost, such as host 28, through a similar voice/data link. Alternatively,hosts 26 and 28 may receive call information directly from clearinghouse22 over data link 31.

Hosts 26 and 28 are shown for clarity, but it should be understood thatmany other hosts may be similarly coupled to platform 24, otherplatforms, other hosts, or clearinghouse 22. Link 33 between host 26 andhost 28 allows hosts to exchange information. Host 35 may be connectedto host 28 via link 33, such that host 35 receives information solelyfrom host 28. In such a manner, designated hosts in network 10 act ascentral hosts to receive data messages and distribute these messages toother hosts.

FIG. 1 illustrates another cellular system 30, which includes a separatetransmission tower 18 and MTSO 20. Within the operating region ofcellular system 30 are truck trailers 12 and monitoring stations 13equipped with messaging units 16. A platform 25 may be associated withcellular system 30, illustrating that the platform functions can beperformed at distributed locations throughout network 10. However,platform 24 may perform all platform functions for all cellular systems.Moreover, as shown in FIG. 1, platform 24 may be coupled to one or morecellular systems. For example, platform 24 may be coupled to all of theWest Coast cellular systems and platform 25 may be coupled to all of theEast Coast cellular systems. Likewise, platform 25 is a distributedplatform, and is associated with and part of a particular cellularsystem. Platform 25, like platform 24, is coupled to a host, such ashost 28.

Dashed line 32 indicates a link between MTSO 20 and platform 24. With aproposed standard (IS41, revision A), validation of a user can beperformed prior to the placing of cellular calls. For example, at powerup or upon first entry into a particular cellular system, a cellulartransceiver can issue identifiers to MTSO 20 for pre-validation.Alternatively, MTSO 20 can poll a cellular transceiver to provideidentifiers for validation and registration. The pre-validationinformation may be transmitted from MTSO 20 to clearinghouse 22 overdata link 23. Likewise, platform 24 may perform the pre-validationwithout resort to an outside clearinghouse, over link 32. With pre-callvalidation performed by clearinghouse 22, later data messages can besent directly to platform 24 over link 32. It should be understood thatlink 32 may be the same as voice/data link 21, a separate dedicated datalink, or another communications link.

Data link 34 between platform 24 to platform 25 allows distributedplatforms to exchange information regarding user validation, fraudmanagement, systems operation, and billing functions. The distributedplatform embodiment also provides fault tolerant and traffic managementfeatures in network 10, not unlike those features found in conventionallong-distance telephone systems. Thus, as is shown in FIG. 1,telecommunications platforms may be centrally located or arranged in adistributed manner and connected by data link 34.

Throughout this description of the invention, host 26, platform 24,clearinghouse 22, MTSO 20, and cellular system 14 have been discussed asseparate elements. It should be understood that each of these componentsare logical components, and they may be combined without physicalseparation. For example, the functions of platform 24 and host 26 may beaccomplished at a single site. Furthermore, the functions of platform 24and clearinghouse 22 may also be accomplished at a single site.References to cellular system 14, MTSO 20, clearinghouse 22, platform24, and host 26 are to be understood as also referring to any cellularsystem, switch, clearinghouse, platform, and host, respectively, ofnetwork 10.

Also illustrated in FIG. 1 is data link 36, which allows for datatransfer between MTSOs of the cellular systems in network 10. Such alink may be an SS7 backbone link for linking cellular systems. Link 36allows cellular systems to share information relating to validation,roaming, billing, call routing, and other functions performed by network10. For example, one cellular system that knows the location of aparticular cellular transceiver, such as the cellular transceiver inmessaging unit 16, may share that information with other cellularsystems. Platform 24 may tie into link 36 across link 21 or link 32 toaccess information exchanged among MTSOs of the cellular systems innetwork 10.

The description of FIG. 1 references both data links and voice/datalinks. Data links, such as links 23, 27, 31, 34, and 36, allowtransmission of data over a dedicated data channel. Voice/data links,such as links 21 and 29, support transmission of voice over a voicechannel and transmission of data over a data channel. For example,cellular telephone transmission over a voice/data link may employdigital transmission techniques to carry voice over a voice channel anddata over a data channel, such as a control channel, paging channel, oroverhead message stream. It should be understood that the inventioncontemplates any transmission technique over a voice/data link, whetherdigital or analog, that provides a voice channel and a data channel.Current systems used in the industry include the DS-1 standard used inthe United States and the CCITT primary multiplex standard used inEuropean telecommunication systems. Communications system 10 alsosupports any suitable modulation techniques, such as time divisionmultiple access (TDMA), frequency division multiple access (FDMA), andcode division multiple access (CDMA).

Another communications protocol contemplated by the invention, termedcellular digital packet data (CDPD), sends data in packets interspersedbetween voice transmissions. The data messages in this protocol may becarried in a reserved section of the digital bit stream or selectivelyplaced to fill unoccupied sections of the digital bit stream. CDPDtechnology also supports delivery of data messages that is notreal-time. This is accomplished by establishing delivery addresses, so auser may receive and store data messages at a designated address andretrieve the data messages at a later time for processing.

Voice/data links also support transmission of data over a voice channelusing a modem, dual-tone multifrequency (“DTMF”) tones, or othersuitable data encoder. The invention contemplates two ways to send adata message in network 10, data transmission over a data channel anddata transmission over a voice channel using a data encoder. It shouldbe understood that a dedicated data channel, such as link 34, could bereplaced with a link that also allows voice transmission, withoutdeparting from the intended scope of the present invention.

In operation, network 10 allows data messages to be sent across cellularsystems, such as cellular systems 14 and 30, in a variety of ways. Datamessages sent to or received from messaging units 16 over a voicechannel in network 10 must pass through platform 24 or 25, where theyare subject to a handshake protocol to minimize cellular telephone fraudand maintain secured communications.

Data messages may also be sent to or received from messaging unit 16over a data channel in network 10. As described below, these messagesare packaged and sent over a data channel as part of the call dataprocessing or call delivery procedures. Like data messages sent over avoice channel of network 10, data messages sent over a data channel mayalso be subject to a security protocol. Each type of data messagingsupported by network 10 will be discussed in detail with reference toFIGS. 3 and 4.

FIG. 2 is a block diagram of a messaging unit 16 operating withinnetwork 10 of FIG. 1. In one embodiment of the invention, messaging unit16 may be attached to a mobile item, such as a truck trailer 12, cargocontainer, other vehicle, or person. However, it should be understoodthat data messaging in network 10 is not limited to truck trailermonitoring systems. Messaging unit 16 may also be attached to a fixeditem, such as monitoring station 13, metering device, or any other itemthat generates information for communication to a remote site.

As shown in FIG. 2, cellular transceiver 38 is coupled to cellulartransceiver bus 40. Cellular transceiver 38 receives and transmitssignals across cellular antenna 42, including cellular transmission andreception of voice and data over the voice and data channels in network10. Cellular transceiver 38 may be just a cellular transmitter equippedto transmit data messages or just a receiver equipped to receive datamessages. It should be understood that further references to cellulartransceiver 38 contemplate a transmitter, a receiver, or both.

Cellular transceiver bus 40 is coupled to one or more processors 44through cellular interface drivers 46. Cellular interface drivers 46provide the necessary protocol for communications between processor 44and cellular transceiver 38.

A modem 48 allows processor 44 to receive and transmit digitalcommunication over a voice channel in network 10, as received from andtransmitted through cellular antenna 42 and cellular transceiver 38.Modem 48, or any suitable device, distinguishes between voice and dataencoded on the voice channel, and handles the information accordingly.

Processor 44 is also coupled to a DTMF recognizer 50. DTMF recognizer 50allows reception and transmission of DTMF data over a voice channel ofnetwork 10, as received from and transmitted through cellular antenna 42and cellular transceiver 38. All data transmissions to or from messagingunit 16 can be made using DTMF data.

Processor 44 is also coupled to a read-only memory (“ROM”) 52 and arandom access memory (“RAM”) 54. These memories are for storage ofinstructions and data for operation of processor 44. It should beunderstood that the invention contemplates use of any other suitablestorage devices (not shown) including, but not limited to, hard disk andfloppy disk drives, optical disk drives, CD-ROM storage devices, tapebackups, and plug-in memory modules. A real-time clock 56 providesprocessor 44 with time-of-day, day-of-week, month, or year information.

In a particular embodiment, messaging unit 16 may provide for input oflocation information from a LORAN-C system, global positioning satellite(GPS) system, dead reckoning system, inertial navigation system, or anysuitable system providing location information. A positioning systeminterface 58 provides location information to processor 44, as receivedfrom positioning system transceiver 60 through positioning systemantenna 62. The location information sent to processor 44 from thepositioning system can be either raw location data (for example, datadirectly received from a LORAN-C system) or processed location data.Therefore, the processing of raw location data can occur within thepositioning system itself, within the positioning system interface 58,within processor 44, or transmitted through cellular transceiver 38 andcellular antenna 42 for later processing at platform 24 or host 26 ofFIG. 1.

Messaging unit 16 also allows for input of status information throughsensor system 64. In one embodiment, sensor system 64 comprises sensors,controllers, and processors used to monitor various parameters of trucktrailer 12 or monitoring station 13, and operates to pass statusinformation to processor 44. Sensor system 64 may monitor performanceparameters of truck trailer 12, such as the temperature of arefrigerated compartment, battery voltage levels, or diagnostics ofother truck trailer subsystems. Sensor system 64 may also monitor thestatus of truck trailer 12 and its contents, such as whether trucktrailer 12 is connected to a cab and whether the contents have beentampered with. In a further embodiment, sensor system 64 may generateinformation about an item associated with monitoring station 13, such asa gas meter, electric meter, other utility meter, vending machine, orother item that generates information for communication to a remotesite. For example, monitoring station 13 associated with a gas meter maygenerate and communicate in a data message information related to meterreadings, customer usage statistics, billing information, or any otherinformation generated at the customer premises. For purposes of thisdescription, “sensor” refers to any device that furnishes processor 44with information about a mobile or fixed item, including location andstatus information.

A power supply 66 powers the various components of messaging unit 16.For clarity, the power connections to the different components ofmessaging unit 16 are not shown. Power supply 66 is a power managementsystem which may include a battery and charging circuitry. In addition,power supply 66 may include optional sources of power, such as anexternal power connection 68 from, for example, a truck electricalsystem interconnection cable, a solar cell 70, a utility connection, orother external power source. Messaging unit 16 may comprise any suitablearrangement and placement of its components in one or more separatehousings attached to the mobile or fixed item.

In operation, messaging unit 16 generates a data message to be sent overvoice or data channels of network 10 upon the occurrence of a reportingevent. The occurrence of a reporting event is determined by processor 44executing a reporting event determination module 72, shown as a part ofprocessor 44 in FIG. 2. Upon the occurrence of a reporting event,processor 44 may immediately generate and transmit a data message orgenerate and store the data message for later transmission. By storingdata messages, messaging unit 16 may then send a batch of data messageschronicling the status of truck trailer 12 or monitoring station 13 overa period of time.

One reporting event that may trigger generation of a data message is atime-out signal received by processor 44 from real-time clock 56.Therefore, messaging unit 16 may generate data messages and reportinformation about a mobile or fixed item at a particular time interval,such as twice a day, every day, or every week, or at a scheduled time ofday, week, or month. In addition, a reporting event may be an externalrequest from a variety of sources, such as MTSO 20, clearinghouse 22,platform 24 and host 26, among others.

A reporting event may also be initiated by the transportation system,metering device, or its operator. For example, messaging unit 16 maygenerate and transmit a data message upon a signal, received byprocessor 44 from sensor system 64, indicating connection ordisconnection of truck trailer 12 from the cab. Also, messaging unit 16may generate and transmit a data message upon a signal generated by ametering device indicating connection or disconnection from a gasutility, electric utility, or other monitored system. An operator of thetransportation equipment or metering device may also manually requestmessaging unit 16 to send a data message.

A reporting event may occur in response to a performance or alarm signalreceived by sensor system 64 that is beyond predetermined limits. Forexample, a reporting event may be when the cargo temperature in arefrigerated truck trailer exceeds a certain minimum or maximum level.Similarly, a reporting event may occur when a metering device sensesmalfunction, tampering, or other condition to be monitored. Thepredetermined limits that trigger a reporting event may be remotelyconfigured from the clearinghouse 22, platform 24, or host 26. Processor44 may also determine a reporting event upon improper access to thecargo hold, malfunctioning of truck trailer subsystems, ormalfunctioning of messaging unit 16 itself.

Furthermore, a reporting event may be based on geographical information.For example, messaging unit 16 may generate a data message when thetruck trailer location determined by the positioning system deviatesfrom an expected truck trailer location. The expected location may bestored in memory such as ROM 52, RAM 54, or other storage device,computed by processor 44, or received from host 26 or platform 24.

In a similar manner, a reporting event may occur when truck trailer 12approaches or crosses a city, state, or national border, or enters theservice area of a cellular system. Therefore, processor 44 executingreporting event determination module 72 causes messaging unit 16 togenerate a data message upon the occurrence of a reporting event. Thereporting event may be based on time, external requests, sensor inputs,manual requests, geographical information, or any other event orcondition that warrants reporting of a data message to host 26.

Upon determination of a reporting event, messaging unit 16 operates totransmit and receive a variety of data messages over network 10. Thedata messages may contain information that initiated the reportingevent, such as a signal indicating connection of the truck trailer to acab, and also other monitored information, such as the location of thetruck trailer at the time of the reporting event or information about anitem generated by or in association with a metering device. Ultimatelydata messages transmitted from messaging unit 16 are routed throughplatform 24, clearinghouse 22, or both and accessed by host 26, as shownin FIG. 1. A data message may be communicated over network 10 usingeither a voice channel or a data channel.

Messaging unit 16, through control of processor 44 may transmit andreceive data messages over a voice channel through platform 24. Forclarity, the transmission or reception of data messages over a voicechannel, including handshaking, will be discussed in connection withmodem transfers, it being understood that such transmissions can be madeusing DTMF tones or other data encoded on the voice channel.

The ability to require that all data messages communicated over a voicechannel pass through platform 24 is an important advantage of theinvention, and allows for modem handshaking between platform 24 andmessaging unit 16. As shown in FIG. 2, processor 44 runs instructionsthat execute a handshake protocol module 74 which establishes securedata modem communication with platform 24. The method to transmit datamessages over a voice channel is described in more detail with referenceto FIG. 3.

Processor 44 also executes a MIN statusing module 76 and a featurerequest generation module 78, which allow messaging unit 16 to generateand transmit data messages over a data channel of network 10. Asdescribed below with reference to FIG. 4, MIN statusing module 76 allowsmessaging unit 16 to encode, reflect, or otherwise associate informationabout a fixed or mobile item by altering identifiers of cellulartransceiver 38, such as the mobile identification number (MIN) orelectronic serial number (ESN), transmitted over a data channel ofnetwork 10. Feature request generation module 78, also discussed withreference to FIG. 4, is another method to send data messages over a datachannel by appending to a feature request data digits representingstatus and location information.

Link 80 between processor 44 and the transportation system or meteringdevice allows messaging unit 16 to send and receive communications toand from, for example, a truck cab or monitoring station 13. The linkmay allow two-way communications using a short range radio system, aninfra-red (IR) coupling, a direct connection through signal wires, orother appropriate technology. Alternatively, the link may be a one-waycommunications link that allows messaging unit 16 to send data messagesfor transmission by the transportation system. In one embodiment, aone-way link may allow a scanner attached to the transportation systemto identify the attached truck trailer 12.

Functionally, link 80 allows components of messaging unit 16 to bedivided between the item and its transportation system. In oneembodiment, processor 44 residing on the item generates a data messageand then sends this data message over link 80 for transmission bycellular transceiver 38 located on the transportation system. In such amanner, the cost of outfitting items with data messaging capabilitiesmay be reduced by placing components of messaging unit 16 on thetransportation system. It should be understood that the inventioncontemplates any arrangement of components of messaging unit 16 on themobile item and the transportation system.

FIG. 3 is a flow diagram for sending a data message generated bymessaging unit 16 over a voice channel of network 10 using a modemhandshake protocol. The method begins at block 100 which determineswhether one of a variety of reporting events has occurred, as determinedby processor 44 running reporting event determination module 72. If noreporting event has occurred, the method loops back in a continuousfashion to monitor the existence of a reporting event. When a reportingevent occurs, block 102 generates a data message. The data message maycontain information about the item in a standard data package fortransmission by modem 48. It should be understood that the inventioncontemplates any suitable modem transfer protocol and compressiontechnique to prepare the data for transmission by modem 48.

The method of FIG. 3 then proceeds to block 104 where messaging unit 16establishes a data modem connection with platform 24 over a voicechannel of voice/data link 21 or 32. Data modem connection establishesthe parameters for communication, such as baud rate, parity, and numberof stop bits. After the connection is established, block 106 initiates amodem handshake between messaging unit 16 and platform 24. If messagingunit 16 does not pass the modem handshake and establish securecommunications with platform 24, the method proceeds to block 108, wherethe communication is disconnected. At block 110, messaging unit 16 maytry to reestablish a data modem connection and retry modem handshaking.Alternatively, the process may be reset for detection of anotherreporting event at block 100.

Upon successful modem handshake, the method proceeds to block 112 wheremodem 48 downloads the contents of the data message into a storagedevice in platform 24. The data may be time-stamped and stored as anentry in a log of data messages from messaging unit 16. Platform 24 canalso index received data messages by an identification number ofmessaging unit 16 or cellular transceiver 38 received during modemhandshaking at block 106. At block 114, an external device, such as acomputer at host 26, can access the stored data messages and update arecord containing information about items equipped with messaging units16.

FIG. 4 is a flow diagram for sending a data message over a data channelof network 10 using either the MIN statusing 76 or feature requestgeneration 78 modules of processor 44. Unlike data messaging using modemdata or DTMF tones, the following discussion describes transmission ofdata messages through network 10 using a data channel, such as a controlchannel, paging channel, overhead message stream, SS7 link, or otherappropriate data link. Furthermore, the data messaging techniquesdescribed below can be routed through clearinghouse 22, platform 24, orboth clearinghouse 22 and platform 24.

The method of FIG. 4 begins at block 116 which determines whether areporting event has occurred by executing reporting event determinationmodule 72 in processor 44. If no reporting event has occurred, themethod continues to monitor sensor system 64, real-time clock 56,location data received from positioning system interface 58, informationreceived from transportation system or metering device, and other inputsto determine if a reporting event has occurred.

Upon the occurrence of a reporting event, block 118 generates a datamessage. As described above, data messages may be created and sentimmediately or created and stored for later transmission by messagingunit 16. A data message for transmission over a data channel of network10 may be generated in two ways. First, messaging unit 16 can encode,reflect, or otherwise associate information about the item by alteringidentifiers of cellular transceiver 38, such as the mobileidentification number (MIN) or electronic serial number (ESN). A secondway to generate a data message is by generating a feature request andappending information about the item in digits of data within thefeature request. These two different ways of generating a data messageare described in detail below.

The process to alter identifiers of a cellular transceiver 38 totransmit a data message, termed MIN statusing, begins withidentification of the event or information to be reported and atranslation of this event or information into a coded number. Forexample, assume processor 44 of messaging unit 16 associated with trucktrailer 12 receives a reporting event signal from sensor system 64indicating that the temperature in the refrigerator compartment of trucktrailer 12 is too high. Processor 44 translates the reporting eventinto, for example, a two-digit status code “39”. The MIN of cellulartransceiver 38 may be altered to include status code “39” in adesignated data field. For example, if the current MIN is “099 8811234”, then the new altered MIN with the embedded status code may be“099 880 0039”. The prefix “880” indicates that the MIN has been alteredto convey information about the item, and the last four digits containthe encoded information in the form of a two-digit status code “39”.

In another example, processor 44 of messaging unit 16 associated with agas meter receives a signal from sensor system 64 indicating the currentreading of the gas meter. Processor 44 translates the gas meter readinginto, for example, a value “134.56” representing the number of cubicfeet of gas detected by the gas meter. The ESN of cellular transceiver38 may be altered to include “134.56” in a designated data field. Forexample, if the current ESN is “0123456789”, then the new altered ESNwith the embedded value may be “1100013456”. Again, a prefix “11”indicates that the ESN has been altered to convey information about theitem, and the last eight digits contain the value generated by the gasmeter.

In the first example above, the MIN of cellular transceiver 38 isaltered to include a data message, but the ESN remains fixed to be usedas an identifier of the messaging unit 16 that sends the data message.Therefore, upon receipt of the MIN/ESN, clearinghouse 22 or platform 24can identify the messaging unit 16 by the ESN and can also receiveinformation about the item encoded in the MIN. In the second exampleabove, processor 44 alters the ESN of cellular transceiver 38 and keepsthe MIN constant. It should be understood that the inventioncontemplates modification of the MIN, ESN, both the MIN and ESN, orother identifiers of cellular transceiver 38 to accomplish the dual taskof encoding information about the item and identifying messaging unit16. Also, the messaging capacity, specific encoding technique, andformat and structure of the altered identifiers may depend on thespecific data messaging application and the specific cellular telephonetechnology employed.

One of ordinary skill in the art can appreciate the reduced cost andcomplexity of sending information about a fixed or mobile item byaltering or encoding identifiers of cellular transceiver 38. The MIN,ESN, or other identifiers may be modified using any appropriatetechnique. The alteration may be on a bit, byte, or multi-byte level,and can include various compression, run length encoding, errorcorrection, or other techniques well-known in the art of digitalcommunication to increase reliability and capacity. In one embodiment,cellular transceiver 38 may include a number assignment module (NAM)that may be programmed to accomplish the MIN statusing. Also, thepresent invention contemplates the retrofitting of existing equipmentthat may not support modification of the MIN or ESN to capture andmodify the MIN/ESN before transmission to MTSO 20. The present inventioncontemplates any suitable technique in hardware or software to alter ormodify identifiers of cellular transceiver 38.

In a particular embodiment using MIN statusing or feature code requestmessaging, messaging unit 16 may receive a communication from MTSO 20indicating the success or failure of the message delivery. For example,a voice channel assign message may indicate that the data message wassent successfully. Similarly, a reorder or intercept message received bycellular transceiver 38 from MTSO 20 may indicate that the data messagecould not be sent. Upon receiving a communication from MTSO 20,messaging unit 16 may resend the data message, log the data message assent, or perform any other appropriate function in response.

Cellular transceiver 38 may transmit identifiers to MTSO 20 upon a call,feature request, pre-call validation, registration of cellulartransceiver 38 with the cellular telephone network, or othercommunication between cellular transceiver 38 and MTSO 20. Therefore,the MIN statusing techniques of the invention can be used alone or inconnection with feature request data messaging, data messaging over avoice channel of network 10, or any other data messaging technique thatalso transmits identifiers of cellular transceiver 38.

A second way to generate a data message at block 118 is to use a featurerequest and append or include information about an item in designateddata digits of the feature request. A feature request is a message fromcellular transceiver 38 to MTSO 20 which is encoded similar to a callrequest. However, MTSO 20 interprets the message as a feature requestbecause of special coding in the message or because of specialinstructions (e.g., class of service restrictions) associated with theMIN, ESN, or other identifier of the cellular transceiver 38. A featurerequest may look like a call request to a number that begins with, forexample, a “*” followed by a two digit code, followed by data digits.The MTSO 20 interprets the “*” and two digits as a feature request andperforms an associated function for that feature request. A featurerequest can be any call request message or similar communication whichthe MTSO 20 interprets differently from a call request. For example, afeature request may have a “*” or may not, or may have a feature requestcode or may not. Current and future cellular systems may support avariety of structures and processing techniques for different kinds offeature requests. The present invention generally contemplates datamessaging using any of these feature request technologies.

Feature requests come in several varieties. For example, some featurerequests are intercepted and acted upon by MTSO 20, such as “*18” and“*19” used to establish and disconnect roaming services. Other featurerequests, such as programmed speed dial numbers, may indirectly resultin the dialing of a telephone number. Messaging unit 16 may issuefeature requests to network 10 using DTMF tones, synchronous orasynchronous digital communication, or any other suitable communicationtechnique supported by MTSO 20.

A dedicated feature request intercepted by MTSO 20 may be specificallyimplemented to transmit data messages. Such dedicated feature requestsallow messaging unit 16 to send detailed data messages containing, forexample, accurate location information generated by the positioningsystem. As an example, a data messaging feature request termed “*17” isgenerated by automatically or manually dialing the star key “*”, atwo-digit feature request identification code “71”, and twenty-ninedigits of data. Furthermore, cellular transceiver 38 automaticallyappends the MIN/ESN to a feature request transmission. Such a featurerequest generated by messaging unit 16 and sent over a data channel ofthe cellular system would allow appended data messages of twenty-ninedigits or more depending on the specific implementation.

Using the gas meter example described above with respect to MINstatusing, the gas meter reading of “134.56” may be encoded or otherwiserepresented in data digits that follow a “*71” feature request.Assuming, for example, ten data digits are available in the featurerequest, cellular transceiver 38 would issue or generate a featurerequest comprising a feature request code (*71) and ten appended datadigits (0000013456). The zeros in this feature request may be furthermodified to encode additional information, such as the identity of thegas meter, its location, or other relevant information regarding themonitored item.

It can be appreciated that messaging unit 16 may generate differentfeature request codes to support different data messaging functions innetwork 10. These different feature request codes may be processed anddirected differently through components of network 10 to provideenhanced feature code data messaging. For example, network 10 maysupport different feature request codes for different data digit sizesand formats, different customers, different communication systems, orother purposes. In a particular example, a feature request may includeall or nearly all data digits without the need for a feature requestcode. In this manner, network 10 captures and processes the transmissionusing the MIN/ESN information included with the feature request.

Upon generating a data message using either MIN statusing 76 or featurerequest generation 78, the method of FIG. 4 proceeds to block 120 whereMTSO 20 receives the data message. MTSO 20 may directly recognize theMIN/ESN or feature request identification code as identifying a datamessage from messaging unit 16. For example, MTSO 20 may be directed torecognize and process in a special manner all communications from aparticular predetermined portion of the MIN/ESN, such as all MINsbeginning with “099 880”. Alternatively, MTSO 20 may be directed torecognize and process in a special manner all feature requesttransmissions with a particular feature request identification code,such as “71”.

In another embodiment, MTSO 20 may contain a separate processor thatindirectly monitors the call transactions through MTSO 20. The separateprocessor may also recognize and process data messages from messagingunit 16 in the same manner described above. In either situation, MTSO 20appends a mobile serving carrier I.D. (“MSCID”) to the MIN/ESN at block122 and routes the data message to clearinghouse 22 over data link 23 orplatform 24 over voice/data link 21 or 32.

In one embodiment, the data message is received directly atclearinghouse 22, as shown in block 124. In another embodiment shown inblock 126, the data message is received at platform 24 directly throughvoice/data links 21 or 32, or indirectly through data link 27 fromclearinghouse 22. An optional security protocol is performed at block127 to ensure the authenticity of the data message. At block 128, themethod identifies the particular messaging unit 16 that is reporting thedata message using the MIN/ESN or other identifiers of cellulartransceiver 38 or messaging unit 16. The data message is thenrecognized, translated, or decoded to obtain the information about anitem reported by messaging unit 16. This step of obtaining informationabout the item may be performed at platform 24, clearinghouse 22, orMTSO 20. In a particular embodiment, MTSO 20 may be equipped with a homelocation register (HLR) that, among other things, provides theprocessing to obtain this information.

The method of FIG. 4 continues at block 130 where each data message maybe time-stamped, indexed by identification number, and stored for laterretrieval. The method of FIG. 4 concludes at block 132, where anexternal device, such as a computer at host 26, can access the storeddata messages and update a record containing information about the itemsequipped with messaging units 16, and thus allow appropriate responsesto the data messages.

Throughout the discussion of FIGS. 3 and 4, the data messages aretransmitted by messaging unit 16 to be collected at a central location,such as clearinghouse 22, platform 24, or host 26. It should beunderstood that messaging unit 16 equipped with cellular transceiver 38may also receive data messages from a central location. The datamessages may be sent from a central location to messaging unit 16 over avoice or data channel of network 10 and in a similar manner as describedabove with reference to FIGS. 3 and 4. For example, data messagesreceived by messaging unit 16 may be sent over a data channel using MINstatusing or feature request generation, over a voice channel using adata encoder such as a modem or DTMF recognizer, or by encoding data ina page request or other call processing communication from MTSO 20 tomessaging unit 16. Received data messages at messaging unit 16 may servea variety of functions, such as remotely programming predeterminedsensor reporting limits, updating messaging unit 16 software, requestinginformation, operating metering device or monitoring station 13, oralerting the operator of the transportation system, among others.

FIG. 5 is a block diagram of a nation-wide cellular network 210constructed according to the teachings of the present invention. Asshown in FIG. 5, a vehicle 212 and a monitoring station 213 is withincellular system 214. Vehicle 212 and monitoring station 213 include acommunication unit 216, which will be discussed in detail below.Cellular system 214.includes transmission towers 218 (only one tower isshown for clarity, it is being understood that each cellular systemincludes a plurality of transmission towers). Cellular system 214 alsoincludes a central mobile telecommunications switching office (MTSO) 220coupled to the transmission tower 218.

MTSO 220 switches calls to and from the cellular system 214 and the landbased telecommunications system. MTSO 220 is also coupled toclearinghouse 222. The link between MTSO 220 and clearinghouse 222 is adata link, and clearinghouse 222 provides call validation information toMTSO 220. For example, MTSO 220 can be configured to connect calls onlyif clearinghouse 222 provides validation information on the call, suchas that the cellular phone involved has good credit, or is authorized tomake calls. Clearinghouse 222 may also maintain other information, suchas information on “roaming” phones' present locations, and home systems.In existing cellular systems, companies such as GTE/TSI, EDS, and McCawprovide the clearinghouse function.

MTSO 220 is also coupled to telecommunications platform (“platform”) 224through a telecommunications link 221 allowing both voice and datatransmissions. Clearinghouse 222 is also coupled to platform 224. Inturn, platform 224 is coupled to central hosts 226 and 228. Centralhosts 226 and 228 are shown for clarity. It should be understood thatmany other central hosts may be similarly coupled to platform 224.Furthermore, other cellular systems will also be coupled totelecommunications platform 224. For clarity, FIG. 5 illustrates oneother such cellular system, cellular system 230. As shown, cellularsystem 230 also includes transmission towers and an MTSO.

Dashed line 232 indicates a link between MTSO 220 and platform 224. Witha proposed standard (IS41, revision A), validation of calls can beperformed prior to the placing of cellular calls. For example, at powerup, or upon first entry into a particular cellular system, a cellularphone can issue its identification numbers, and pre-validation can beperformed. Alternatively, the MTSO 220 can poll communication unit 216to request identification for validation and registration. Thepre-validation may be between MTSO 220 and a clearinghouse, such asclearinghouse 222. Likewise, platform 224 may perform the pre-validationwithout resort to an outside clearinghouse, over link 232. With pre-callvalidation performed by clearinghouse 222, later data transmissions,such as feature requests, can be sent directly to platform 224 over link232. It should be understood that link 232 may be the same as link 221.

In operation, nation-wide cellular network 210 operates to controlaccess to and information sent across cellular systems such as cellularsystems 214 and 230. In particular, all calls to or from communicationunit 216 must pass through telecommunications platform 224. In oneembodiment, communication unit 216 may be associated with certain classof service restrictions maintained by the cellular carrier that specifythat all calls made from communication unit 216 be directed to platform224. Therefore, calls to and from communication unit 216 are controlledto limit access to and time on cellular system 214. The details of thiscontrol will be discussed below.

FIG. 6 illustrates an alternate embodiment of the present inventionwhich includes distributed telecommunications platforms. FIG. 6 includesthe elements described above in connection with FIG. 5, with theexception that the telecommunications platform is distributed.Illustrated in FIG. 6 are platforms 234 and 236. In contrast to platform224 of FIG. 5, which is centrally located and to which all cellularsystems are connected, platforms 234 and 236 may be distributedthroughout the nation-wide cellular network. As shown in FIG. 6,platform 234 may be coupled to one or more cellular systems. Forexample, platform 234 may be coupled to all of the West Coast cellularsystems and platform 236 may be coupled to all of the East Coastcellular systems. Likewise, platform 236 is a distributed platform, andis associated with and part of a particular cellular system.

Also shown in FIG. 6 is a communications link 237 from platform 234 toplatform 236 that allows the distributed platforms to exchange voice anddata, which may include user activity, systems operation, and billingfunctions. In particular, the distributed platforms 234 and 236 canexchange information regarding user validation and fraud management. Thedistributed platform embodiment also provides fault tolerant and trafficmanagement features to the nation-wide cellular telephone system, notunlike those features found in conventional long-distance telephonesystems. Thus, as is shown in FIGS. 5 and 6, telecommunicationsplatforms may be centrally located or distributed, as required by theneeds of the particular system implementing the present invention.

Also illustrated in FIG. 6 is link 239. Link 239 allows for datatransfer between MTSOs of various cellular systems. Such a link may bean SS7 backbone link for linking cellular systems. Link 239 allowscellular systems to share information such as validation, roaminginformation, billing, and call routing, among other types ofinformation. For example, one cellular system that knows the location ofa particular cellular phone, such as communication unit 216, may sharethat information with other cellular systems. Platform 224, across link232, may tie into link 239. This allows platform 224 to have access toall MTSO 220s of different cellular systems.

FIG. 7 illustrates a communication unit 216 constructed according to theteachings of the present invention. Communication unit 216 includes allof the functions of messaging unit 16 illustrated in FIG. 2, butcontains additional components to provide interactive telephone and dataservices to the user. In one embodiment, messaging unit 16 may operatewithout user intervention and communication unit 216 supports userinteraction. As shown in FIG. 7, phone transceiver 238 and hand set 240are coupled to cellular phone bus 242. Phone transceiver 238 receivesand transmits signals across antenna 244, including cellulartransmission and reception of voice, data, and DTMF data, among othersignals. The cellular phone bus 242 is coupled to processor 246 throughphone interface drivers 248. Phone interface drivers 248 provide thenecessary protocol for communications between the processor 246 and thephone transceiver 238 and hand set 240.

A hands-free microphone 250 and speaker 252 are provided for hands-freecommunications by the operator of the communication unit. The hands-freemicrophone 250 and speaker 252 are coupled to audio multiplexer 254.Audio multiplexer 254 is also coupled to the hand set 240, the cellularphone bus 242, and the processor 246. The audio multiplexer 254 is alsocoupled to a modem 256 and a voice recognition and synthesis system 258.The modem 256 allows for digital communication between the processor 246and the cellular system, as received from and transmitted throughantenna 244 and phone transceiver 238. Modem 256, or any suitabledevice, is used to distinguish between voice and data and handle theinformation accordingly. Voice recognition and synthesis system 258allows for voice activation of various functions of the communicationunit. Voice recognition and synthesis system 258 is coupled to processor246.

Processor 246 and audio multiplexer 254 are also coupled to a dual-tonemulti-frequency (“DTMF”) recognizer 259, which allows for recognition ofDTMF data. All data transmissions to or from communication unit 216 canbe made using DTMF.

Communication unit 216 also allows for reception and storing oftelephone numbers. These numbers may be received as modem or DTMF data,and may be recalled and automatically dialed. Furthermore, processor 246of communication unit 216 can execute software allowing for voice mailfunctions for calls to communication unit 216.

Processor 246 is also coupled to a read-only memory 260 and a randomaccess memory 262. These memories are for storage of instructions anddata for operation of processor 246. Furthermore, a plug-in ROM module264 may also be coupled to processor 246 for optional information, suchas map and emergency assistance information for a particular locality.

A key pad 266 is provided for user input of various information into thecommunication unit 216 through processor 246. It should be understoodthat key pad 266 could comprise many other input devices, such as atouch screen. Information is displayed at communication unit 216 throughgraphic display 268, which is driven by processor 246 through displaydrive 270.

Communication unit 216 allows for input of location information from aLORAN-C system, a global positioning satellite (GPS) system or anysuitable system providing location information of the communicationunit. This input is shown by positioning system 272 in FIG. 7. Thepositioning system 272 may be located within the housing of thecommunication unit 216, or part or all of positioning system 272 may belocated outside the communication unit 216. The data sent to thecommunication unit 216 from positioning system 272 can be either rawlocation data (for example, data directly received from LORAN-C system)or processed location data. Therefore, the processing of raw locationdata can occur within the positioning system 272 itself, withinprocessor 246, or transmitted through phone transceiver 238 and antenna244 for later processing at the platform 224 or central host 226 of FIG.5.

Communication unit 216 also allows for input of status informationthrough automatic status generator 274. The automatic status generator274 comprises any sensors, controllers, and processors used to monitorperformance parameters of the vehicle 212 or monitoring station 213, andoperates to pass information from such monitors to communication unit216. As will be discussed, status information may be received by thecommunication unit 216 from either the automatic status generator 274 orthe key pad 266. Block 276 allows for the input or output of variousother options, such as an alarm input which, for example, could indicatethat a vehicle or metering device on which the communication unit 216 islocated has been broken into. As other examples, block 276 allows forthe input or output of fax data or digital data to or from a modem. Suchinputs and outputs may be from personal computers, for example, fromusers of recreational vehicles or traveling salesmen. Throughout thisdiscussion, data communications, including handshaking, will bediscussed in connection with modem transfers for clarity, it beingunderstood that such transmissions can be made as DTMF data. A powersupply 278 powers the communication unit 216.

In operation, communication unit 216 operates to transmit and receiveinformation, including voice and data, across a cellular system andthrough telecommunications platform 224 of FIG. 5. Ultimately, datatransmitted from communication unit 216 is sent through platform 224 toone of the central hosts, for example central hosts 226 or 228 shown inFIG. 5.

Communication unit 216, through control of processor 246, receives allcalls through telecommunications platform 224, and makes all outgoingcalls through telecommunications platform 224. This restriction isaccomplished through use of a handshake protocol. The details of thisprotocol will be discussed below in connection with calls to or from thecommunication unit. The ability to require that all calls to and fromthe communication unit pass through platform 224 is an importantadvantage of the present invention, and allows for control of thecharacter and length of calls made to and from the communication unit.This is important in reducing cellular telephone usage costs, forexample for a nation-wide trucking company, in which the truckingcompany provides communication units in each of the trucks of the fleet,and wishes to restrict the character and length of calls from and to thecommunication units.

The communication unit 216 allows for transmission and reception of bothvoice and data. The voice transmissions, once a call is connected, areperformed conventionally. Hands-free microphone 250 and speaker 252allow for hands-free voice communications.

Data received by communication unit 216 is input to the processor 246through modem 256. Data transmitted from communication unit 216 istransmitted under control of the processor 246 through modem 256. Datato be transmitted from communication unit 216 may be input in severalways. Key pad 266 may be used by a user of the communication unit 216 toinput various data, such as location data or status data (for example,whether a vehicle is broken down, whether it is loading, unloaded,waiting to load, waiting to unload, whether a meter has been read,disconnected, or reset, etc.). Such data may also be input by voicecommand through voice recognition and synthesis system 258. Data mayalso be automatically generated for output by communication unit 216.For example, positioning system 272, which may comprise a LORAN-Cpositioning system, a GPS system, or any other positioning system, maygenerate position location information for transmission by communicationunit 216.

As discussed above, positioning system 272 may generate longitude andlatitude information, or simply raw data, for example from a GPS system,to be transmitted from communication unit 216. If only raw data isgenerated by a positioning system 272, then processor 246, the platform224, or the central host 226 can generate the longitude and latitudeinformation for positioning information. Likewise, automatic statusgenerator 274 may be used to automatically generate status information,such as engine performance, trailer temperature (for example, if arefrigerated trailer tractor is associated with the communication unit),or other status information.

Processor 246 drives graphic display 268 through display driver 270 todisplay data received by communication unit 216 for viewing by a user ofcommunication unit 216. Such data, for example, may be messages from acentral host on weather conditions, delivery or destinationinstructions, among other messages. Furthermore, plug-in ROM 264provides various information, such as map information or emergencyassistance information for use by a user of the communication unit 216.This information can be displayed on graphic display 268.

FIG. 8 illustrates a block diagram of telecommunications platform 224constructed according to the teachings of the present invention. Aprocessor 280 is coupled to memory 282, look-up tables 284, and switch286. Processor 280 is also coupled to fraud management system 287, usagetracking system 288, and billing system 290. In the distributed platformembodiment of FIG. 6, processor 280 may also communicate with anotherplatform through communications link 291. Switch 286 is coupled totelecommunications trunks 292 and 294. Trunk 292 allows fortelecommunications connections to central hosts, such as central hosts226 and 228 of FIG. 5, as well as other outside land-based systems. Asshown in FIG. 8, some of the individual telecommunications lines oftrunk 292 are coupled to modems, such as modems 296 and 298, thusallowing for data communications. Likewise, trunk 294 allows fortelecommunications connections with various cellular systems, such ascellular systems 214 and 230 of FIG. 5. Some of the individualtelecommunications lines are coupled through modems, such as modems 300and 302, so as to allow for data communications with the cellularsystems. Modems 296 and 300 are illustrated as MODEM/DTMF, to indicatethat DTMF data can be transmitted and received as well. Modems 296, 298,300 and 302 are coupled to processor 280 and can also operate to allowboth voice and data communications. Trunks 292 and 294 are separated forclarity to show one bank of telecommunications lines serving dispatchersand other outside systems while another bank serves cellular systems.However, switch 286 can contain a single trunk or several trunks toaccomplish the operations of the platform.

Telecommunications platform 224 operates as a smart telecommunicationsswitch. Calls to and from communication unit 216 are passed throughswitch 286. Processor 280 monitors switch 286 and records information oneach call through switch 286. This information, such as the number andlength of calls to each communication unit 216, is recorded in usagetracking system 288. In this manner, bills can be generated for usage oftelecommunications platform 224. Typically there will be severalcommunication units associated with a particular system, such as atrucking system or utility meter monitoring system. Thus, all calls toand from communication units owned by a system will be logged forbilling to that particular system.

As discussed previously, a fraud management system 287 performs ahandshake protocol between the telecommunications platform 224 and thecommunication unit 216. This protocol ensures than only authorized callsare made to and from communication unit 216. If the handshake protocolis not performed correctly, then processor 280 will disconnect the callthrough switch 286, thereby greatly reducing costs resulting fromunauthorized usage of cellular networks. Processor 280 also links tocredit card validation system 303, to validate credit cards for allowingfor personal calls, as will be discussed.

FIG. 9 is a flow diagram for transmission and reception of a “present”message according to the teachings of the present invention.Communication unit 216 of the present invention, upon entry into a newcellular system, issues a present message which will eventually be sentto its central host. The “present” message can also be generated inresponse to a poll from platform 224 or MTSO 220, periodically, uponpower up of communication unit 216 upon re-establishment ofcommunication, through use of a feature request reserved for the“present” message, or during pre-call or post-call validation, amongother events. This “present” message can also be sent automatically ormanually, and provides information to the central host on the currentcellular system in which the communication unit is located. Furthermore,other information, such as status information, can be sent with this“present” message. An important technical advantage of the presentinvention is the fact that this “present” message may be sentautomatically, and with a minimum of cellular air time, thus providingsignificant cost savings. The “present” message may be sent to platform224 through clearinghouse 222, through link 221 (for example, as part ofa call), or through link 232 of FIG. 5.

Turning to the flow diagram of FIG. 9, at decision block 304,communication unit 216 monitors the system identification number of theparticular cellular system in which it is located. This systemidentification number, as is generally known in the art, is periodicallyissued by the cellular system in the control channel, paging channel,overhead message stream, or other appropriate data channel. Once thecommunication unit 216 identifies a new system identification number,indicating that the communication unit has entered a new system, itissues a “present” message at block 306. For example, the “present”message can be initiated by transmitting a “*19” feature request.Presently, “*19” is used in mobile systems to clear the roaming statusof a cellular phone. As discussed above, the “present” message can alsobe generated upon other events, such as power up of the communicationunit 216.

Every cellular phone has associated with it a mobile identificationnumber (“MIN”) and an electronic serial number (“ESN”). These numbersare transmitted by the cellular phone whenever it makes a call or issuesa feature request, such as “*19.” Certain digits of the ESN are used bylocal cellular carriers. The unused digits may be used by communicationunit 216 to send information, such as location or status data. Forexample, longitude and latitude data can be embedded in the unusedportion of the ESN. Likewise, certain digits of the MIN may not benecessary to identify calls to be directed to platform 224, and thusdata may be embedded in these unused digits. Thus, the “present” messagemay contain important data as well. At block 308, the “present” messageis received at MTSO 220 of FIG. 5. The MTSO 220 typically appends thecellular system identification number plus a switch identificationnumber to the MIN and ESN numbers. As discussed, the “present” messagemay also be sent as part of a call from the communication unit 216, andthus is sent to platform 224 across link 221.

When the “*19” is received at the clearing house 222 at block 310, itwill determine whether the “present” message is to be sent to thetelecommunications platform 224 at block 312. If the “present” messageis not to be sent to the platform, then no data is sent. Theclearinghouse 222 determines whether the “present” message is to be sentto the platform 224 by matching all or a portion of the MIN/ESN of thecommunication unit to numbers stored in a pre-established user database. This data base is established by making arrangements with theclearinghouse 222 that all communications from particular cellularphones, i.e., the communication units 216, will be recognized by theirMIN/ESN and directed to the platform 224. This data base can also beestablished such that even with a communication unit registered at somehome cellular system, the “present” message will be directed to theplatform 24.

As discussed above, a direct link 232 may exist between MTSO 220 andplatform 224. This link 232 allows for direct transmission of data andfeature requests, such as the “*19” feature request and “present” datamessage, to the platform 224. MTSO 220 can be configured to directlysend such transmissions by pre-arranging with MTSO 220 to recognizeparticular communication units 216, or by forwarding such instructionsfrom clearinghouse 222 as part of a pre-call validation scheme.

One embodiment allows the clearinghouse 222 to identify thecommunication units 216 by a specified area code and prefix of the MIN.Upon matching the registered communication units 216 with the user database in the clearinghouse 222, the “present” message is sent to theplatform 224 at block 314. The platform then timestamps and stores all“present” messages received from communication unit 216 through thelocal carrier. The platform stores the data under each MIN/ESN for latertransmittal to the central host. For example, a single communicationunit 216 on a truck traveling across the country may send numerous“present” messages to the platform as the truck passes through differentcellular systems. The platform 224 maintains a timestamped chronologicallist of the “present” messages, so the truck company dispatch can accessthe list, determine the location and status of the truck, graph itsroute over time on a map display, and/or compute travel statistics ofthe truck.

The platform 224 of FIG. 8 eventually sends this information to theparticular central host associated with the communication unit 216 asshown at block 316. This transfer of data can occur periodically, suchas at a particular time interval, upon request by a central host, orwhenever a call connection is made between a central host and thecommunication unit 216. It should be understood that there willtypically be a plurality of communication units associated with aparticular central host. For example, the central host may be a truckcompany dispatch that locates and coordinates the activities of a fleetof trucks equipped with communication units 216. Thus, data can be downloaded from the platform 224 to the truck company dispatch anytime acall is made between the dispatch and any of the trucks. Alternatively,the truck company can periodically call the platform, preferably whencall rates are low or on a dedicated or “800” number, and download adata package containing status and location information on the truckfleet. From the “present” message, the central host can determine atleast which cellular system a particular communication unit has entered.This information is available since the MTSO 220 appends information tothe MIN/ESN. Such information may be, for example, a mobile servingcarrier I.D. (“MSCID”). Furthermore, any data, including specificlocation data generated by positioning system 272 or automatic statusgenerator 274, embedded in the ESN/MIN can be extracted by the centralhost.

The ability to generate “present” messages provides a significantadvantage of the present invention. In particular, one centrallocation—the platform 224—maintains these “present” messages and thushas knowledge of the location (at least the cellular system location) ofvarious communication units. This information allows for efficient andinexpensive call delivery. By directing calls to the communication unitsthrough the platform 224, roaming difficulties are eliminated, since theplatform 224 maintains a record of the locations of the communicationunits 216. This call delivery advantage is useful in a wide range ofapplications, such as the broadcasting of messages to distributedcommunication units, like those used in trucking companies, barges,traveling sales forces, rail systems, commercial and private bus lines,airplanes, and rental vehicles, among others. The architecture of thepresent invention also allows for efficient broadcasting of messages tomonitoring stations 213, such as utility metering systems, vendingmachines, and distributed advertising systems. For example, billboardsfor lotteries can be programmed to automatically display the jackpotamount. This amount can be sent across cellular networks, with the callsbeing made through platform 224.

FIG. 10 is a flow diagram of a call made to a communication unitaccording to the teachings of the present invention. FIG. 10, along withFIG. 11 to be discussed below, describe the operation of the fraudmanagement system 287 and the protocol handshake mentioned above.Without a successful handshake, a call cannot be connected either to orfrom a communication unit.

As shown in FIG. 10, a call to a communication unit is first made byplacing a call to the platform at block 318. This call is, for aexample, a 1-800 call, thereby reducing costs to those calling theplatform. At block 320 the platform requests a communication unit I.D.for the communication unit to be called. This communication unit I.D.,for example, could be a truck identification number for communicationunits placed on trucks. If no communication unit I.D. number is receivedor the communication unit I.D. is not proper, then decision block 322returns the flow to block 320. If the communication unit I.D. is proper,then the platform acquires authorization information at block 324.Authorization information may be, for example, a credit card number oran authorized code. For example, personal calls made to thecommunication unit would only be initiated if the caller to the platformgave a valid credit card number. Validation of the credit card numbermay be accomplished through credit card validation system 303 of FIG. 8.For business calls coming from an associated central host, authorizationcan occur by entering an authorized code, or by calling in on a specialbusiness line, for example. This authorization occurs at block 326.

If the call is authorized, then the platform calls a communication unitat block 328. Platform 224 uses look-up tables 284 of FIG. 8 toassociate the phone number of the communication unit to be called withthe communication unit I.D. Platform 224 then looks up the most recentlyrecorded cellular system identification number and switch identificationnumber associated with communication unit 216, such as that provided bythe most recent “present” message issued by communication unit 216 andstored by platform 224. Platform 224 then calls the appropriate roameraccess port, and dials the phone number. Once the call is connected andthe platform and communication unit modems establish data communication,the communication unit 216 issues a challenge at block 330. Thischallenge may be, for example, a random number. If no challenge isreceived, then the platform 224 disconnects the call at block 331. Ifthe platform receives a challenge, then at block 332 the platformreturns a response based on the challenge received, a key particular tothe communication unit, and an encryption algorithm. As noted, the keyused in the generation of the response is a function of thecommunication unit and may be generated from a lookup table of numbersshared by both communication unit 216 and platform 224 indexed by theMIN/ESN of communication unit 216. The encryption algorithm, also knownby both communication unit 216 and platform 224 can be any appropriatemathematical algorithm, and may be modified periodically, as can thelookup table, to maximize security.

At block 334, the platform determines whether the response is correct byrunning the same encryption algorithm on the challenge and key. If theresponse is not correct, or if no response is received, then the call isdisconnected at block 336. U.S. Pat. No. 5,155,689, issued on Oct. 13,1992, and assigned to By-Word Technologies, Inc., of Dallas, Tex.,discloses a system that connects or disconnects calls based uponinterrogation between two modems in a cellular system. That patent isherein incorporated by reference.

If the response is correct, the call is completed at block 338. At block338, either voice or data or both may be transmitted to or from thecommunication unit.

For calls from the central host 226 that include voice communications, avoice request is sent to the platform 224 from the central host 226 tocommunicate with a particular communication unit 216. Any data to beexchanged with that communication unit is exchanged before connectingthe voice communications. For example, data from the central host 226 isdelivered through the platform 224 to the communication unit 216, andany data at communication unit 216 is delivered at least to platform224. Next, the platform 224 requests that communication unit 216 toswitch to voice, and rings the user of communication unit 216. If noanswer is received, then no voice connection is made betweencommunication unit 216 and central host 226. If an answer is received,then platform 224 calls the central host 226 (or any other numberprovided to the platform 224 by the central host) and patches theappropriate connection.

There will be times when calls cannot be delivered to communication unit216, for example, when it is out of any cellular system, temporarily outof communication with a cellular system, or powered-down. In such cases,an alert will be set at the platform 224, indicating that a call has notbeen completed. Upon receipt of a “present” message, for example, whenthe communication unit 216 to which the call was intended powers up,re-establishes communication or enters a new cellular system, theplatform 224 can complete the call. If only data is to be transferred,then this data can be sent from the platform 224 to the communicationunit 216. If a voice call had not been completed, then the platform 224calls the calling party, for example the dispatcher at a central host,and indicates that a call can be or will automatically be placed to theappropriate communication unit 216. Furthermore, the user of acommunication unit 216 may be provided with a pager/remote ringer, toensure that he is aware of any voice calls to his communication unit216.

FIG. 11 is a flow diagram of a call from a communication unit 216according to the teachings of the present invention. At block 340, thecommunication unit initiates an outgoing call. The outgoing call can beinitiated in any of several ways. The communication unit 216 can beprogrammed such that only certain pre-programmed numbers can be called.These authorized phone numbers are stored in communication unit 216 andcan be programmed remotely by the central host 226 or platform 224.Thus, a user of a communication unit would only be able to call thesepre-programmed numbers and no others. Alternatively, the communicationunit could be configured so as to allow personal calls—if eventuallyauthorized—as well as pre-programmed authorized calls. Regardless ofwhat number is to be eventually called, the communication unit 216 ispre-programmed to first call the platform at block 342. This call, forexample, could be a 1-800 number call. Alternatively, arrangements canbe made with each cellular system to direct all calls from communicationunits with particular MIN/ESNs to platform 224. Each local carrier wouldrecognize these particular MIN/ESNs and route their calls to platform224. Recognition can occur through use of a pre-arranged database, asdiscussed above. The handshake protocol between the communication unitand the platform is similar to that described in connection with FIG.10, except that the challenge and response are issued by the platformand communication unit, respectively.

As shown in FIG. 11, at block 344 the platform issues a challenge aftermodem connection with the communication unit and receipt of acommunication unit I.D., such as an MIN. This I.D. provides the platform224 with knowledge of which communication unit is calling. If nochallenge is received, then the communication unit disconnects the callat block 346. If the challenge is received, then the communication unitreturns a response and the platform receives the response at block 348.The response is generated by executing the encryption algorithm on thechallenge and the key particular to the communication unit. If theresponse generated by the communication unit does not match the desiredresponse generated by the platform, as determined at block 350, then thecall is disconnected by the platform at block 352. If the response iscorrect, then the platform receives the ultimate number to be called atblock 354. If it is determined that this ultimate number to be called isone of the pre-programmed calls at block 356, then the call is connectedat block 358. Typically, such a call would be to a user of the centralhost or a customer. In such a case, voice or data or both can betransmitted. If it is determined at block 356 that the ultimate numberto be called is not a pre-programmed number, then an authorizationdecision is made at block 360. For example, block 360 may compromise acredit card authorization step. If there is no authorization for thecall, then the call is disconnected at block 362. If the call isauthorized at block 360, for example by entry of a valid credit cardnumber, then the call will be connected at block 364. For datatransmissions, the data can be stored at platform 224 and transmitted tocentral host 226 at various times, as discussed above in connection with“present” messages.

The system of the present invention provides for several layers of fraudprevention. For calls originating at communication unit 216, a firstlayer of protection is the ability to restrict outgoing calls to onlypre-programmed calls. Thus, a user of communication unit 216 may berestricted from calling any unauthorized numbers.

A second layer of fraud prevention is provided by the requirement thatall calls to or from a communication unit 216 pass through the platform224. To restrict incoming calls, the MIN of the communication unit 216may be chosen so that it is not a dialable number, thereby preventingany unauthorized charges from incoming calls. Arrangements can be madewith each cellular carrier in communications system 10 to set asideblocks of non-dialable numbers for use by communication units 216. Foroutgoing calls, a myriad of “gatekeeping” functions may be performed atthe platform 224. For example, the platform 224 may connect only certainauthorized calls from the communication unit 216, and require a validcredit card for all others calls. Likewise, the platform 224 can ensurethat only authorized calls (such as business calls or credit cardauthorized calls) are directed to the communication unit 216.

A third layer of protection is provided by the handshake protocol of thepresent invention. With this handshake protocol, fraudulent procurementof the MIN/ESN of the communication unit 216 will be to no avail withoutknowledge of the handshake protocol. For example, if a call were placeddirectly to the communication unit 216, through knowledge of its MIN,the call could not be completed without knowledge of the handshakeprotocol.

One of the most popular schemes for defrauding cellular users involvesobtaining the MIN/ESN of a particular communication unit 216, and thencloning a phone with the same MIN/ESN. Such a cloned phone can then beused in most any cellular system, with the cellular usage charges beingbilled to the original communication unit 216 as roamer charges. Thepresent invention foils this variety of fraud by requiring that any callusing the particular MIN/ESN of communication unit 216 be directedthrough the platform 224. As discussed above, this requirement can beaccomplished by making arrangements with the local cellular carriers totrap calls having particular MIN/ESNs and route them to the platform224, or alternatively forcing all communication units to only call theplatform. The platform 224 then requires successful protocol handshakingto connect the call.

Each communication unit 216 may be equipped with a unique handshakeprotocol, and the platform 224 would maintain a data base thatassociated each communication unit 216 with its unique handshakeprotocol. Alternatively, a library of handshake protocols can bemaintained, with each communication unit 216 assigned one of thehandshake protocols from that library. The platform 224 would then keepa record of which protocol of the library is assigned to a particularcommunication unit 216, and perform handshake protocols accordingly.

The handshake protocol described herein provides an excellent means ofpreventing cellular fraud. It should be understood, however, thatcommunication unit-cellular system-telecommunications platformarchitecture of the present invention provides technical advantages evenwithout the fraud prevention technique. For example, the ability togather information on the cellular system location of the communicationunits 216 allows for efficient call delivery to these communicationunits.

Throughout this description of the invention, the central host 226, theplatform 224, the clearinghouse 222, and the cellular system 212 havebeen discussed as separate elements. It should be understood that eachof these components are logical components, and they may be combinedwithout physical separation. For example, the functions of the platform224 and the central host 226 may be accomplished at a single site.Likewise, the functions of the platform 224 or clearinghouse 222 may beperformed at the local cellular system, for example, at the MTSO.

The present invention has been discussed in connection with cellularsystems. It should be understood that it may also be used in connectionwith satellite telecommunications systems. For example, the transmissiontowers 218 and MTSO 220 of FIG. 5 may be replaced with, or used inconjunction with, a satellite telecommunications system. Furthermore,transmissions to and from the communication unit 216 may be acrossvarious channels, such as separate data and voice channels using, forexample, packet data communications.

FIG. 12 is a block diagram of the central host 226 constructed accordingto the teachings of the present invention. As shown in FIG. 12, acentral host includes a processor 366 coupled to memory 368. Datatransmitted to and received from communication units is transmittedthrough modem 370 to and from processor 366. Such data may be stored inmemory 368 and displayed on display 372. Furthermore, various data, suchas data to be transmitted to communication units, is input through userinput/output 374. Data which may be input through user input/output 374,for example, may include the text data to be transmitted to a particularcommunication unit. Such text data could include particular messages,such as changes in delivery schedules, weather conditions, or the like.Such data is displayed on display 268 of communication unit 216, asshown in FIG. 7. Voice communications between a central host andcommunication units may be made through voice phone 376. Throughout thisdescription in drawings, separate communications have been shown fordata and voice, with the data passing through a modem. It should beunderstood that a single telecommunications line may be used to provideboth voice and data without departing from the intended scope of thepresent invention.

In operation of central host 226 of FIG. 12, data and messages receivedfrom communication units may be displayed on display 372 and output, forexample in hard copy form, through user input/output 374. For example, amap with location identification of each communication unit associatedwith the central host is displayed on display 372. In this way, thecentral host 226 can keep track of the location and progress ofcommunication units and vehicles associated with the communicationunits. The processor 366 runs software which allows automated sending ofdata to particular communication units. This data can be automaticallygenerated by processor 366 or input through user input/output 374.Central host can also receive raw location information, that can then beprocessed in processor 366 to generate latitude and longitudecoordinates.

Processor 366 may also, by tracking the locations of communicationunits, based on longitude and latitude and road map information,determine how many miles each communication unit travels within aparticular state. From this information, fleet mileage reports can begenerated, for example for trucking companies. These fleet mileagereports can be used to determine the distance traveled and amount offuel used in various states, which allows for accurate reporting forboth fuel and road usage taxes. Furthermore, knowledge of the locationof vehicles at particular times, for example from “present” messages orgeographic location data, allows for a graphical display of the route ofa truck over time and the calculation of estimated times of arrivals andother travel statistics by dispatchers at central hosts. For example,knowledge that a truck is in Dallas, Tex. on Thursday night allows foran estimate of arrival time in Mobile, Ala.

Although the present invention has been described in severalembodiments, a myriad of changes, variations, alterations,transformations, and modifications may be suggested to one skilled inthe art, and it is intended that the present invention encompass suchchanges, variations, alterations, transformations, and modifications asfall within the spirit and scope of the appended claims.

What is claimed is:
 1. A system for communicating information about anitem using a cellular telephone network, comprising: a messaging unitoperable to communicate, using a data channel of a cellular telephonenetwork, a feature request having data digits that represent informationabout the item; and a remote site coupled to the cellular telephonenetwork and operable to receive the feature request communicated by themessaging unit to obtain information about the item.
 2. The system ofclaim 1, wherein the remote site stores information represented by thedata digits of the feature request.
 3. The system of claim 2, comprisinga host coupled to the remote site and operable to access the informationstored by the remote site.
 4. The system of claim 1, comprising a switchcoupled to the cellular telephone network and operable to recognize thefeature request and, upon recognition, route the feature request to theremote site.
 5. The system of claim 1, wherein the messaging unit isattached to a trucking trailer located within a service area of thecellular telephone network.
 6. The system of claim 1, wherein themessaging unit is attached to a metering device.
 7. The system of claim1, wherein the remote site is operable to translate the data digits ofthe feature request into information on a reporting event and to storethe information on the reporting event.
 8. A method for data messagingusing a cellular telephone network, comprising: obtaining informationabout an item; generating a feature request having data digits thatrepresent information about the item; communicating the feature requestusing a data channel of a cellular telephone network; and receiving thefeature request at a remote location.
 9. The method of claim 8, whereinthe step of obtaining information about the item occurs upon receiving arequest to initiate data messaging from the remote location.
 10. Themethod of claim 8, wherein the step of obtaining information about theitem comprises generating information about the item using a sensor. 11.The method of claim 8, wherein the step of communicating the featurerequest comprises: receiving the feature request at a switch;recognizing the feature request at the switch as a feature request fordata messaging; and communicating the feature request from the switch tothe remote location upon recognition.
 12. The method of claim 8, whereinthe feature request comprises a feature request code and the step ofcommunicating the feature request comprises: receiving the featurerequest at a switch; recognizing the feature request code at the switch;and communicating the feature request from the switch to the remotelocation upon recognition of the feature request code.
 13. The method ofclaim 8, wherein the feature request comprises a cellular transceiveridentifier and the step of communicating the feature request comprises:receiving the feature request at a switch; comparing the cellulartransceiver identifier to a plurality of stored identifiers associatedwith data messaging; and communicating the feature request from theswitch to the remote location if the cellular transceiver identifiermatches one of the stored identifiers associated with data messaging.14. The method of claim 8, wherein the step of receiving comprises:receiving the feature request at a remote location; identifying amessaging unit that transmitted the feature request; translating thedata digits to determine information about the item; and storinginformation about the item indexed by the messaging unit for access by ahost.
 15. The method of claim 8, wherein the step of receivingcomprises: receiving the feature request at a remote location;identifying a messaging unit that transmitted the feature request;translating the data digits to determine information about the item; andstoring information about the item in a time-stamped list of informationreceived from the messaging unit for access by a host.
 16. The method ofclaim 8, wherein the feature request comprises an altered identifier ofa cellular transceiver that reflects information about the item.
 17. Themethod of claim 8, wherein the step of generating a feature request isperformed automatically.
 18. A method for data messaging using acellular telephone network, comprising: generating information about anitem using a sensor; generating a feature request having data digitsthat represent information generated by the sensor; communicating thefeature request using a data channel of a cellular telephone network;and receiving the feature request at a remote location.
 19. The methodof claim 18, wherein the sensor is a positioning system that generateslocation information on the item.
 20. The method of claim 18, whereinthe feature request comprises a feature request code, and furthercomprising: receiving the feature request at a switch; recognizing thefeature request code at the switch; and communicating the featurerequest from the switch to the remote location upon recognition of thefeature request code.
 21. The method of claim 18, wherein the featurerequest comprises a cellular transceiver identifier, and furthercomprising: receiving the feature request at a switch; comparing thecellular transceiver identifier to a plurality of stored identifiersassociated with data messaging; and communicating the feature requestfrom the switch to the remote location if the cellular transceiveridentifier matches one of the stored identifiers associated with datamessaging.
 22. The method of claim 18, further comprising storinginformation generated by the sensor in a time-stamped list ofinformation.
 23. The method of claim 18, wherein the feature requestcomprises an altered identifier of a cellular transceiver that reflectsinformation generated by the sensor.
 24. The method of claim 18, whereinthe item is a vehicle and the sensor is coupled to the vehicle.
 25. Themethod of claim 18, wherein the step of generating a feature request isperformed automatically.
 26. A system for data messaging using acellular telephone network, comprising: a messaging unit operable toobtain information about an item, the messaging unit further operable togenerate a feature request having data digits that represent informationabout the item, the messaging unit comprising a cellular transceiveroperable to communicate the feature request using a data channel of acellular telephone network; a platform coupled to the cellular telephonenetwork, the platform operable to receive the feature requestcommunicated by the messaging unit to obtain information about the item;and a host coupled to the platform and operating external to thecellular telephone network, the host operable to access informationabout the item obtained by the platform.
 27. The system of claim 26,wherein the feature request comprises a feature request code, andfurther comprising a switch coupled to the cellular telephone network,the switch operable to receive the feature request communicated by themessaging unit and to communicate the feature request to the platformupon recognition of the feature request code that indicates datamessaging.
 28. The system of claim 26, wherein the feature requestcomprises a cellular transceiver identifier, and further comprising aswitch coupled to the cellular telephone network, the switch operable toreceive the feature request communicated by the messaging unit and tocommunicate the feature request to the platform upon matching thecellular transceiver identifier with one of a plurality of storedidentifiers associated with data messaging.
 29. The system of claim 26,wherein the messaging unit further comprises a sensor operable togenerate information about the item.
 30. The system of claim 26, whereinthe messaging unit further comprises a positioning system operable togenerate location information about the item.
 31. The system of claim26, wherein the item is a vehicle and the messaging unit is coupled tothe vehicle.
 32. The system of claim 26, wherein the feature requestcomprises an altered identifier of a cellular transceiver that reflectsinformation about the item.
 33. The system of claim 26, wherein themessaging unit automatically generates the feature request.
 34. A systemfor data messaging using a cellular telephone network, comprising: amessaging unit having a sensor operable to generate information about anitem, the messaging unit further operable to generate a feature requesthaving data digits that represent information generated by the sensor,the messaging unit comprising a cellular transceiver operable tocommunicate the feature request using a cellular telephone network; aswitch coupled to the cellular telephone network, the switch operable toreceive the feature request communicated by the messaging unit and tocommunicate the feature request to a platform if the feature requestindicates data messaging; the platform coupled to the cellular telephonenetwork, the platform operable to receive the feature requestcommunicated by the switch to obtain information generated by thesensor; and a host coupled to the platform and operating external to thecellular telephone network, the host operable to access informationobtained by the platform.
 35. The system of claim 34, wherein the switchcommunicates the feature request to the platform upon recognition of afeature request code included in the feature request.
 36. The system ofclaim 34, wherein the feature request comprises a cellular transceiveridentifier associated with the cellular transceiver of the messagingunit, the switch operable to store a plurality of identifiers associatedwith data messaging, the switch further operable to communicate thefeature request to the platform upon matching the cellular transceiveridentifier with one of the identifiers stored at the switch.
 37. Thesystem of claim 34, wherein the sensor comprises a positioning systemoperable to generate location information about the item.
 38. The systemof claim 34, wherein the feature request comprises an altered identifierof the cellular transceiver that reflects information generated by thesensor.
 39. The system of claim 34, wherein the item is a vehicle andthe sensor is coupled to the vehicle.
 40. The system of claim 34,wherein the messaging unit automatically generates the feature request.41. A messaging unit for data messaging using a cellular telephonenetwork, comprising: a sensor operable to generate information about anitem; a processor coupled to the sensor and operable to receiveinformation generated by the sensor, the processor further operable togenerate a feature request having data digits that represent informationgenerated by the sensor; and a cellular transceiver operable tocommunicate the feature request using a data channel of a cellulartelephone network.
 42. The messaging unit of claim 41, furthercomprising a memory coupled to the processor, the memory operable toaccumulate information generated by the sensor, wherein the processorgenerates a feature request having data digits that representinformation accumulated in the memory.
 43. The messaging unit of claim41, wherein the item comprises a vehicle and the sensor comprises anengine sensor.
 44. The messaging unit of claim 41, wherein the sensorcomprises a positioning system operable to generate location informationabout the item.
 45. The messaging unit of claim 41, wherein theprocessor automatically generates the feature request.
 46. A method forcommunicating information using a cellular telephone network, the methodcomprising: generating information on an item using a sensor; generatinga feature request having data digits that represent informationgenerated by the sensor; and communicating the feature request using acellular transceiver coupled to a data channel of a cellular telephonenetwork.
 47. The method of claim 46, further comprising the step ofaccumulating in a memory information generated by the sensor.
 48. Themethod of claim 46, further comprising the step of altering anidentifier of the cellular transceiver to reflect information generatedby the sensor.
 49. The method of claim 46, wherein the sensor comprisesa positioning system operable to generate location information about anitem.
 50. The method of claim 46, wherein the step of generating afeature request is performed automatically.